OBID i-scan
®
Application Note
RFID-Tunnel
FEIG ELECTRONIC GmbH
Page 39 of 54
N70101-2de-ID-B.doc
E N G L I S H
3
Mounting and Connecting
3.1 Size of the Antennas
The size of the antennas is dictated by the required reading area and distance. The reading area
corresponds approximately to the antenna area. The reading distance of an antenna should be at
least half of the distance to the opposing antenna of the gate. (see example Fig. 7)
Fig. 7
Basically the antenna size shouldn’t be chosen larger than necessary, because with increasing
antenna size the reading distance also increases, but the magnetic field strength decreases.
Further more:
•
In this suggested solution two parallel antennas are connected to a gate. For each reading ori-
entation two antennas respectively one gate are necessary.
•
The size of each an antenna of the RFID-Tunnel shouldn’t fall below 250mmx250mm, other-
wise the inductance of the antenna will be to low and will be outside the automatic tuning range
of the ID ISC.DAT antenna tuning board.
•
The best ratio of the sides of an antenna is 1:1 (square).
•
The ratio of the sides of an antenna shouldn’t exceed 3:5 (e.g. 300mmx500mm)
50cm
min. 25cm
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